This invention relates to thermosetting polymers prepared from methylated pyridines or pyrazines, aromatic dialdehydes, isopropenyl phenols, and with or without bismaleimides.
In the aerospace and/or aircraft industry there is a need for light weight fire resistant polymeric composites for interior and exterior use. A recent development in this critical area was the discovery that composites based on polystyrylpyridines are useful in this field of endeavor. The key patents are outlined below.
It is known from U.S. Pat. No. 3,994,862 that polystyrylpyridine thermosetting prepolymers and cured polymers can be obtained by reacting methylated pyridines and aromatic dialdehydes.
U.S. Pat. No. 4,163,740 discloses the preparation of solutions of polystyrylpyridines in various organic solvents such as ethyl acetate, propanol, and methylethylketone.
U.S. Pat. No. 4,362,860 discloses related polystyrylpyridines terminated with vinyl pyridine.